package org.example.JUC.AQS;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.AbstractQueuedSynchronizer;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;

/**
 * @description:
 * @author: farprt
 * @create: 2022-08-22 15:02
 **/
public class NonReentrantLock implements Lock,java.io.Serializable{

    private static class Sync extends AbstractQueuedSynchronizer{

        //是否锁已经被持有
        protected boolean isHeldExclusively(){
            return super.getState()==1;
        }

        //若state为0尝试获取锁
        public boolean tryAcquire(int acquires){
            assert acquires==1;
            if(compareAndSetState(0,1)){
                super.setExclusiveOwnerThread(Thread.currentThread());
                return true;
            }
            return false;
        }

        //尝试释放锁，设置state为0
        protected boolean tryRelease(int releases){
            assert releases==1;
            if(super.getState()==0){
                throw new IllegalMonitorStateException();
            }
            setExclusiveOwnerThread(null);
            setState(0);
            return true;
        }

        Condition newCondition(){
            return new ConditionObject();
        }
    }

    private final Sync sync =new Sync();

    @Override
    public void lock() {
        sync.acquire(1);
    }

    @Override
    public boolean tryLock() {
        return sync.tryAcquire(1);
    }

    @Override
    public void unlock() {
        sync.release(1);
    }

    @Override
    public Condition newCondition() {
        return sync.newCondition();
    }

    public boolean isLocked(){
        return sync.isHeldExclusively();
    }

    @Override
    public void lockInterruptibly() throws InterruptedException {
        sync.acquireInterruptibly(1);
    }

    @Override
    public boolean tryLock(long time, TimeUnit unit) throws InterruptedException {
        return sync.tryAcquireNanos(1,unit.toNanos(time));
    }




}